Tomo-PIV measurements of flow around a slender body at high angles of attack

Abstract

Detailedmeasurements and analysis of temporal and spatial scales inherent in the unsteady asymmetric wake vortex flow generated by a slender axisymmetric body at high angle of attack are performed. Tomographic Particle Image Velocimetry measurements are carried out at 40° angle of attack and Reynolds number ranges from 1.0 × 104to 4.5 × 104. Results show the presence of two main asymmetric counter rotating vortices. The Reynolds numbers affect the configuration of these vortices where vortex flipping occurred at the lowest Reynolds number investigated. Time-averaged vorticity contours and instantaneous streamlines are presented. Timeaveraged vorticity suffered from the expected smoothing of details that have short duration. Instantaneous flowfield data such as streamlines shows possible interaction between the main vortices and model attached vortices. Also, the core of the two main vortices can be seen to be affected by the presence of multiple vortex filaments.